Yeah, looking at it again this morning, I think it works pretty well with the two tones of red. Really makes it look like there's a G1 Ironhide in there with new parts on the outside.
Of course, not all the vehicle reds match up perfectly, but that's Hasbro's fault
I used the cut-away leg mod for Ironhide (same as Megatron), while Prime has his legs extended. Worked out nicely since, even though they're the same mold, Prime is still taller. Keeps the cartoon scale somewhat intact.
Typically, I don't like big insignias visible in the vehicle modes, but after seeing plenty of pick-up trucks roaming around with custom graphics, it doesn't seem too out-of-place on Ironhide. It discerns him from Prime in vehicle mode, too.